000
FXUS65 KVEF 021719
AFDVEF
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LAS VEGAS NV
1019 AM PDT SUN AUG 2 2015
.SYNOPSIS...A FEW SHOWERS AND THUNDERSTORMS ARE EXPECTED AGAIN TODAY
AND EARLY EVENING MAINLY EAST AND NORTH OF LAS VEGAS AS A WEAK
DISTURBANCE MOVES NORTH THROUGH THE REGION. OVERNIGHT TONIGHT...MUCH
DRIER AND MORE STABLE AIR WILL WORK INTO THE REGION CONFINING ANY
STORMS TO MAINLY NORTHERN INYO AND ESMERALDA COUNTIES MONDAY. DRY
CONDITIONS ARE EXPECTED TUESDAY AND WEDNESDAY...BUT THUNDERSTORMS
CHANCES WILL CREEP BACK INTO MOHAVE COUNTY BY THE END OF THE
WEEK.
&&
.UPDATE...CIRCULATION NOTED EARLIER WAS NEAR THE NV/AZ/UT TRIPLE
POINT THIS MORNING AND MOVING NORTH. THUNDERSTORMS ASSOCIATED WITH
IT HAD BEEN SLOWLY DECREASING THROUGH THE MORNING. FORECAST TRENDS
LOOK GOOD AND NO UPDATE PLANNED THIS MORNING.
&&
.PREV DISCUSSION...
238 AM PDT SUN AUG 2 2015
.SHORT TERM...TODAY THROUGH TUESDAY NIGHT.
MORNING RADAR IMAGERY SHOWING SHOWERS AND ISOLATED THUNDERSTORMS
STRETCHING FROM JUST NORTH OF KINGMAN NORTH ACROSS EASTERN CLARK
COUNTY AND INTO LINCOLN COUNTY. THESE SHOWERS AND STORMS ARE BEING
AIDED BY THE FORCING OF THE TAIL END OF THE DISTURBANCE THAT PUSHED
THROUGH THE REGION YESTERDAY. THIS DISTURBANCE IS EXPECTED TO
CONTINUE LIFTING NORTH DURING THE DAY...BUT IS MOVING RATHER SLOWLY
AND HAVE INCREASED POPS THIS MORNING OVER THE EASTERN HALF OF CLARK
AND CENTRAL AND NORTHERN MOHAVE COUNTIES. AS THIS FEATURE LIFTS
NORTH WE SHOULD SEE PLENTY OF NVA AND MORE STABLE AIR WORKING INTO
THE SOUTHERN HALF OF THE AREA WHICH WILL LIMIT ANY SHOWERS AND
STORMS TO MAINLY CENTRAL NYE...LINCOLN AND NORTHERN MOHAVE COUNTIES
THIS AFTERNOON. SLIGHT CHANCES WILL ALSO OCCUR OVER NORTHERN INYO
AND ESMERALDA COUNTIES. BY TONIGHT MOST OF THE AREA WILL BE UNDER
FAIRLY STABLE AND DRY CONDITIONS WITH ONLY SLIGHT CHANCES OF
PRECIPITATION OVER THE FAR NORTHERN PORTIONS OF THE CWA. MONDAY WILL
CONTINUE THE TREND OF DRIER AND MORE STABLE CONDITIONS AS A
DEVELOPING TROUGH OFF THE WEST COAST BRINGS IN A MUCH DRIER AND MORE
STABLE SOUTHWEST FLOW. DID LEAVE IN A SLIGHT CHANCE OF POPS OVER
NORTHERN INYO COUNTY WHERE SOME RESIDUAL MOISTURE AND WEAK
INSTABILITY RESIDE...BUT THOSE CHANCES ARE SLIGHT. DRY CONDITIONS
EXPECTED EVERYWHERE TUESDAY AS THE SOUTHWEST FLOW PUSHES ANY
REMAINING MOISTURE OUT OF THE AREA. TEMPERATURES WILL REMAIN A
COUPLE OF DEGREES BELOW NORMAL TODAY AND THEN CLIMB TO NEAR TO
SLIGHTLY ABOVE NORMAL BY MONDAY AND TUESDAY.
.LONG TERM...WEDNESDAY THROUGH SUNDAY.
THE LONG TERM PERIOD BEGINS WITH A SERIES OF SUBTLE SHORTWAVES
TRAVERSING THE GREAT BASIN AHEAD OF A DEVELOPING UPPER LEVEL LOW OFF
OF THE CENTRAL CALIFORNIA COAST. THESE WAVES WILL YIELD AN INCREASE
IN MID TO HIGH LEVEL CLOUD COVER OVER THE INYO AND SOUTHERN GREAT
BASIN ZONES WEDNESDAY AFTERNOON THROUGH THURSDAY. HOWEVER...THE BIG
STORY WILL BE THE MOISTURE RETURN EXPECTED AS THIS SYSTEM APPROACHES
THE COAST. OPERATIONAL MODEL GUIDANCE AND ASSOCIATED ENSEMBLES
CONTINUE TO BE CONSISTENT IN THE PLACEMENT OF THE UPPER LOW...AS
WELL AS THE HIGH TO THE EAST NEAR THE FOUR CORNERS REGION...ALLOWING
MOISTURE TO BE DRAWN UP FROM THE GULF OF CALIFORNIA BEGINNING
THURSDAY. ALL INGREDIENTS WILL LIKELY BE IN PLACE...INCLUDING
ABUNDANT MOISTURE WITH PWAT VALUES OVER 1 INCH
POSSIBLE...PARTICULARLY OVER MOHAVE COUNTY...FORCING WITH THE
ADVANCING UPPER LOW AND ASSOCIATED SURFACE FRONT...AND SUFFICIENT
INSTABILITY FOR THUNDERSTORMS ACROSS AT LEAST THE EASTERN ZONES.
THEREFORE...OPTED TO RAISE THUNDERSTORM CHANCES OVER MOHAVE
COUNTY...AS WELL AS EASTERN CLARK AND LINCOLN COUNTIES THURSDAY
THROUGH SATURDAY MORNING. DECIDED TO KEEP THE LAS VEGAS VALLEY OUT
OF THE ACTION FOR NOW...AS MINOR CHANGES IN THE TIMING AND
PROGRESSION OF THIS WAVE COULD SPELL THE DIFFERENCE BETWEEN SEEING
SHOWERS AND STORMS AND REMAINING DRY. AS FOR THE NORTHWEST
ZONES...DUE TO CONCERNS OVER THE AMOUNT OF AVAILABLE MOISTURE AND
INSTABILITY...AS WELL AS 35-45 KTS OF SHEAR DOWNSTREAM OF THE UPPER
LOW...DECIDED TO RAISE POPS TO ALLOW FOR A CHANCE OF THUNDERSTORMS
IN THE SIERRA AND WHITE MOUNTAINS OF INYO COUNTY FRIDAY AFTERNOON.
OUTSIDE OF THE INCREASED THUNDERSTORM CHANCES...THIS SYSTEM WILL
REINTRODUCE BELOW AVERAGE TEMPERATURES FOR THE WEEKEND...WITH
AFTERNOON HIGHS RUNNING 4-5 DEGREES BELOW NORMAL...AND POSSIBLY
FALLING JUST SHORT OF THE CENTURY MARK IN LAS VEGAS.
.AVIATION...FOR MCCARRAN...A BAND OF SHOWERS AND A FEW EMBEDDED
THUNDERSTORMS CONTINUE TO MOVE NORTH-NORTHWEST ACROSS THE PEACH
SPRINGS AND MORMON MESA CORRIDORS THIS MORNING. THIS ACTIVITY IS
EXPECTED TO WEAKEN OVER THE NEXT SEVERAL HOURS. THUNDERSTORMS MAY
REDEVELOP OVER THE MORMON MESA CORRIDOR AFTER 18Z...BUT WILL REMAIN
AWAY FROM THE TERMINAL. OTHERWISE...EXPECT DIURNALLY DRIVEN WINDS AT
THE TERMINAL TODAY UNDER GRADUALLY CLEARING SKIES.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...THUNDERSTORM CHANCES WILL BE LIMITED TO
LINCOLN...NYE...ESMERALDA AND NORTHERN INYO COUNTIES ON SUNDAY. LESS
COVERAGE IS EXPECTED THAN WHAT OCCURRED YESTERDAY. ERRATIC GUSTY
WINDS AND MOUNTAIN OBSCURATIONS CAN BE EXPECTED WITH ANY
THUNDERSTORMS IN THESE AREAS. OTHERWISE...EXPECT DIURNALLY DRIVEN
WINDS AT ALL TAF SITES THROUGH TONIGHT WITH CLEARING CONDITIONS AS
DRIER AIR FILTERS INTO THE REGION.
.SPOTTER INFORMATION STATEMENT...SPOTTERS ARE ENCOURAGED TO REPORT
ANY SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING
PROCEDURES TODAY. THE REMAINDER OF THE WEEK LOOKS DRY.
&&
$$
MORGAN/GORELOW/PULLIN
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